Emergency cut-out switch for well pumping mechanism



Jan. 3, 1939. 2,142,551

-ou'r SWITCH FOR WIIJLL PUMPING MECHANISM c. R.ATHY( EMERGENCY GUT 2Sheets-Sheet 1 Filed Oct. 7, 1936 awe/WM c. R. ATHY 2,142,551 EMERGENCYCUT-OUT SWITCH FOR WELL PUMPING MECHANISM Jan. 3, 1939. I

2 Sheets-Sheet 2 Filed Oct. 7, 1936 F v m Patented Jan. 3, 1939EMERGENCY CUT-OUT SWITCH FOR WELL PUltlPING NIECHANISM Clifford R. Athy,Columbus, Ohio, assignor to International-Stacey Corporation, Columbus,Ohio, a corporation of Ohio Application October 7, 1936, Serial No.104,489

9 Claims.

This invention relates to well pumping and drilling mechanism, and hasparticular reference to a well pumping and drilling unit of the powerdriven geared type wherein an oscillatory walking beam is actuated by apower shaft having cranks on the opposite ends thereof, the ends of saidcranks being connected by a pair of pitmans with a transverselyextending equalizing member centrally pivoted to one end of the walkingbeam.

It is an object of the present invention to provide apparatus forautomatically discontinuing the operation of the driving motor or engineof such well pumping or drilling mechanism in the event a wrist pin'orpitman should break or become disconnected or otherwise renderedinoperative in carrying out their intended functions.

In well pumping mechanism of the character under consideration, twinpitmans are connected at the upper ends thereof to an equalizing crossbeam. If a wrist pin should break or if the wrist pin nut should becomeloose so that the wrist pin could come out of the crank opening,

" the opposite pitman would continue to operate the walking beam if thepower were not immediately shut off. Such a disconnected pitman is aptto do considerable damage to a machine, and the pitman which remainsattached to the crank is likely to twist the walking beam and otherwisedamage associated structure.

In accordance with the present invention, the equalizing cross beam, orother corresponding portion of the walking beam to which the upper endsof the twin pitmans are united, is provided with a switch mechanismwhich is used for governing the operation of the control circuit of anengine or motor employed for driving the walking beam, the said switchmechanism during normal operation of the Walking beam serving to providefor the closure of said control circuit but is so formed that in theevent of undue oscillation on the part of the equalizing cross beam, orof distortion of the walking beam proper, the said switch mechanism willoperate automatically to open the control circuit and therebyimmediately arrest the operation of the prime mover, such as an internalcombustion engine or an electric motor, used in imparting power to theapparatus.

It is a further object of the invention to provide a switch mechanismwith a manually operated resetting control so that when said switchmechanism is operated to open the control circuit of the prime mover, itwill be impossible to close the same except by the employment of adeliberate manual operation.

Other objects reside in the provision of a switch mechanism of thecharacter indicated which may be readily applied to well pumpingapparatus of the character indicated, and one which will be small andcompact, will not in any way interfere with the ordinary operation ofthe pumping apparatus, susceptible to convenient adjust ment, andreliable and positive in operation.

For a further understanding of the invention, reference is to be had tothe following description and the accompanying drawings, wherein:

Fig. 1 is a perspective view of a twin pitman well pumping and drillingunit and disclosing the switch mechanism comprising the presentinvention in its operative position thereon;

Fig. 2 is an end elevation of the unit;

Fig. 3 is a vertical sectional view taken through the switch mechanism;

Fig. 4 is a transverse sectional view on the line IV-IV of Fig. 3;

Fig. 5 is a wiring diagram employed by the switch mechanism;

Fig. 6 is a vertical sectional view on the plane indicated by the lineVIVI of Fig. 4;

Fig. 7 is a vertical sectional view through a mercury switch used in themechanism, the plane of the section being indicated by the line V'IIVIIof Fig. 3.

Referring more particularly to the drawings, the sub-frame of a gearedwell pumping and drilling mechanism is indicated at I. Arising from theframe I, which may be composed of structural steel members, is a Samsonframe 2, carrying at the upper end thereof bearings 3 for the rockingsupport of a walking beam 4. The outer end of the walking beam isprovided with the usual head 5 with which cables or other well drillingor pumping tools may be connected. At the opposite end of the walkingbeam, the latter is provided with a longitudinally extending stud 6,upon which is mounted for limited rocking movement a transverselyextending equalizer I. The opposite ends of the equalizer l are providedwith pins 8 to which are pivotally connected the upper ends of a pair oftwin pitmans 9, the lower ends of said pitmans being similarly connectedwith wrist pins l0 extending from the outer ends of a pair of crank armsH, the latter being carried, in turn, by the outer ends of a gear drivenshaft I 2. The shaft is journaled for rotation in connection with a gearhousing l3, bolted or otherwise secured to the sub-frame I and motion isimparted to the gearing (not shown) contained within the housing by theprovision of a suitable prime mover, which may be either an internalcombustion engine or an electric motor, the latter having been shown atI4 in the drawings and as mounted directly on the frame I.

The equalizer is utilized to unite the spaced pitmans with the powerreceiving end of the walking beam and if desired, the said equalizer mayrock about the axis of the stud 5 to compensate for inequalities ofalignment which may exist between the crank arms II and the walkingbeam., In certain instances, however, the equalizer may be welded orotherwise attached to the power receiving end of the walking beam andany inequalities present may be absorbed by the normal flex inherent inthe structural steel beam.

In apparatus of this character, it will be un-. derstood that if one ofthe pitmans should break or become disconnected with its operatingmembers, injury to the machine and to the operators thereofmay readilytake place. In fact, such accidents are not uncommon and have causedconsiderable damage. As a safeguard against such a contingency, thepresent invention provides a switch mechanism, indicated generally bythe letter S, which is so constructed and mounted that when a looseconnection d'evelops between the walking beam 4 and the cranks H, withthe machine in operation, the said switch mechanism will serve tosubstantially immediately arrest the operation of the motor H3 or otherprime mover.

The switch mechanism S comprises a casing as indicated at l5, the saidcasing being preferably mounted on the vertical web |6 of the equalizer1, and firmly secured in connection therewith by means of fasteningbolts Preferably, the casing is disposed contiguous to one of the endsof the equalizer where it will have the greatest amount of motion in theevent of breakage of one of the pitmans.

Lead lines l8 and I9 enter the casing and are connected with anysuitable source of electric current supply, such for instance as abattery or the power lines of a commercial circuit. The lead I8 isconnected with a screw 20 which passes through an insulating panel 2|arranged within the casing, the panel being held in place by contactinglugs 22, projecting inwardly from the corners of the casing and held incontact with said lugs by screws 23. The screw 2|] is connected by meansof a conducting bar 24 with a terminal 25 also carried by the panel 2|,and from the terminal 25, a lead line 26 extends to a strip conductor21. From the conductor 21, a lead 28 extends to the field coil 29 of anelectromagnet 30, the latter being stationarily mounted on a base plate3| carried by the panel 2|. The outgoing lead 32 of the coil 29 extendsto a strip conductor 33 carried by the plate 3|, which is also composedof a dielectric substance, and a wire 3 1 leads from the conductor 33 toa mercury switch 35 of the glass bulb type.

Such switches are of common construction but in the present instancecomprise an enclosed glass bulb containing a limited amount of mercurywhich when the switch is in its normal position electrically unites apair of spaced electrodes 36 carried by one end'of the bulb. The wire 34is connected with one of these electrodes and a wire as indicated at 37is connected with the other thereof. The wire '31 extends to a secondmercury switch 38 which is of the same construction as the switch 35but, as shown in Fig. 3, occupies a reverse angular position withrespect to that normally assumed by the switch 35. Both the switches 35and 3B are received within holders 39 which are pivotally united withthe panel 2|, so that the angularity of said switches may be controlledat will for the purpose of requiring more or less tilting of the switchmechanism S to control the opening of the circuit in which said switchesare positioned.

From the switch 38, a wire 40 extends to a binding post 4| carried bythe base plate 3|, the binding post being connected with a stationarycontact 42. Cooperative with this contact is a movable contact arm 43,which is connected with an armature 44, the latter being pivotallymounted as at 45 in connection with the base plate. When the field ofthe magnet 30 is excited,'the armature is drawn toward the pole piece ofthe magnet against the resistance of a spring 46, so

that the contacts 42 and 43 are brought into physical engagement tocompletethe circuit therethrough. The movable contact arm is connectedwith a conductor 4'! which extends to a binding post 48, the latterbeing joined by a conductor 49 to the lead |9 which connects the switchS with the power line to complete the circuit for the electromagnet 30.A conductor 50 leading from the binding post 4|, connected with thestationary contact of the switch, is joined with a lead 50a of a motorcontrolling circuit, the return lead 50b of the last-named circuit beingconnected with the screw 25. 7

Normally, the armature 44 is disposed beyond the range of magneticattraction of the coil 29 and to bring the contacts 42 and 43 intoengagement, it is necessary to first operate a spring pressed plunger 5|which has an actuating knob 52 disposed exteriorly of the casing I5. Theinner headed end 52 of the plunger is arranged in registration with thearmature 44 and in order to first complete a circuit through the switchmechanism, it is necessary to actuate the plunger 5| to move the sameinwardly of the casing into engagement with the armature and to therebyrock the latter about its axis of pivotal mounting to bring the contacts42 and 43 into relative engagement. This results in completing thecircuit through the coil of the magnet and since the armature will thenbe positioned in the field of said magnet, the latter operates to holdthe spring pressed armature in its position of circuit closure. It willbe understood that the leads 56a and 5% may extend directly to the motorM, or may extend to an operating switch, as indicated at 53, for saidmotor. Again, the leads 50a and 501) may constitute a part'of theignition circuit of an internal combustion engine.

When the equalizing beam 1 occupies its normal horizontal position, theangularity of adjustment of the mercury switches 35 and 38 is such thatboth of these last-named switches will be closed, that is, the mercurycontained therein will cover the spaced electrodes to provide forcurrent travel therethrough. This, as shown more particularly in Fig. 5,provides for current flow through the coil of the magnet 30 from thesource of current supply and as long as the magnet is energized, thearmature 44 thereof will be retained in a position in which the contacts42 and 43 will be in physical engagement. If, however, one of thepitmans should become disconnected from its operating frame or otherwisebroken or injured, the operation of the remaining pitman will causeoscillation of the equalizing beam 1. Oscillation in either direction ofthis equalizing beam, after a predetermined amount of movement, willcause the opening of one or the other of the mercury switches and 38 sothat current flow to the electromagnet will be interrupted.

This enables the spring 46, as well as the action of gravity, tooscillate the armature so that the contacts 42 and 43 will be separatedand therefore interrupting the prime mover circuit involving the leads50a and 50b. This results in automatic and substantially instantaneousstopping of the operation of the prime mover so that injury to theapparatus, or those working around the same, will be minimized.

The construction of the switch S is such that after the electromagnethas been deenergized, it is impossible for the switch to again closeitself. This is due to the fact that the armature is actuated by thespring 46 to completely separate the contacts 42 and 43 and to removethe armature from the field of the magnet coil. Thus after normaloperating conditions of the pumping mechanism have been restored andrepairs made, it is necessary to manually operate the plunger 5! toreset the switch mechanism. By this arrangement, any oscillatorymovement of the equalizing beam, after the switch mechanism has beenactuated to stop the prime mover, would have no effect on the controlcircuit of the prime mover.

In view of the foregoing, it will be seen that the present inventionprovides a simple, automatic and efficient device for protecting twinpitmans pumping apparatus of the character set forth. The switchmechanism is of compact and simple form and when mounted on the equalizing beam, or other equivalent member, does not in any way interfere withthe normal operation of said beam or the parts associated therewith. Theswitch may be installed on existing apparatus of this character as anattachment or, if desired, may be built into newly manufactured pumpingequipment. The mercury switches 35 and 33 occupy fixed angular positionswith respect to each other, although the angularity of said switches maybe regulated by the partial rotation of said switches about the axes ofthe holders 39. The axes of said holders pass through the panel 2| andmay be provided with nuts or the like to bind the holders in desiredpositions of adjustment. As the angularity of the mercury switches isincreased, corresponding greater movement on the part of the equalizingbeam will be necessitated to actuate the switches.

What is claimed is:

1. In well pumping and drilling mechanism, in combination, a walkingbeam, a crank shaft, a pair of pitmans for transmitting motion from saidcrank shaft to said walking beam, a prime mover for driving said crankshaft, said prime mover having a control circuit, and switch meansautomatically responsive to transverse distortion of said walking beamcaused by the loosening or breaking of one of said pitmans to interruptthe control circuit of said prime mover and arrest the operation of thelatter.

2. In well pumping and drilling mechanism, in combination, a walkingbeam, a crank shaft, a pair of pitmans for transmitting motion from saidcrank shaft to said walking beam, a prime mover for driving said crankshaft, said prime mover having a control circuit, and switch meansmounted in connection with said walking beam and automaticallyresponsive to transverse distortion of said walking beam caused by theloosening or breaking of one of said pitmans to interrupt the controlcircuit of said prime mover and arrest the operation of the latter.

3. In well pumping and drilling mechanism, in combination, a walkingbeam pivotally mounted for oscillation in a vertical plane, equalizingmember connected to one end of said walking beam, said equalizing memberbeing disposed in plane transverse to that of the walking beam, 2. pairof cranks carried by a journaled shaft, spaced pitmans uniting saidcranks with the ends of said equalizing member, a motor including acontrol circuit, motion transmitting means between said motor and saidcrank shaft, and a switch mechanism carried by said equalizer andautomatically operative upon predetermined movement of said equalizerfrom its normal operating position to effect the opening of the controlcircuit for said motor to arrest the operation of said motor and theapplication of power to said crank shaft.

i. In well pumping and drilling mechanism, in

combination, a walking beam pivotally mounted for oscillation in avertical plane, a transversely extending equalizing member pivotallymounted for oscillation on one end of said beam in a plane perpendicularto the plane of oscillation of said beam, a shaft having a pair ofcranks, spaced pitmans having their lower ends secured to said cranksand their upper ends secured to the ends of said equalizing member, amotor including a control circuit, motion transmitting means betweensaid motor and said crank shaft for effecting the rotation of thelatter,anda normallyclosed switch mechanism carried by said equalizing memberfor governing the operation of the control circuit of said motor, saidswitch being automatically operative to interrupt said control circuitwhen said equalizing member oscillates through predetermined degrees ofmovement from its normal position.

5. In well pumping and drilling mechanism, in combination, a pivotallymounted walking beam, a motor including a control circuit, motiontransmitting means between said motor and said walking beam, and switchmechanism carried by said walking beam and automatically responsive topredetermined transverse distortion of said beam to interrupt said motorcircuit and automatically discontinue the application of power to saidwalking beam.

6. In well pumping and drilling mechanism, a pivotally mounted walkingbeam, a motor including a control circuit, motion transmitting meansbetween said motor and said walking beam, switch mechanism carried bysaid walking beam and disposed in a plane transverse to that of theplane of oscillation of the walking beam, said switch mechanismincluding a pair of angularly disposed mercury tubes positioned tonormally close said control circuit, and means for adjusting andmaintaining the relative adjustment of said mercury tubes, said tubesbeing automatically operative upon predetermined transverse distortionof said beam to interrupt said control circuit and thereby automaticallydiscontinue the application of power to said walking beam.

7. In well pumping and drilling mechanism, a pivotally mounted walkingbeam, a transversely extending equalizing member carried by said beamcontiguous to one end thereof, means for rocking the walking beam aboutits pivotal mounting, said means having connection with the oppositeends of said transverse member, and mercury switch means carried by saidequalizing member, said switch means being operated by tilting movementof said equalizing member in a plane angular to that of the longitudinalaxis of said beam.

8. In Well pumping and drilling mechanism, a pivot-aliy mounted walkingbeam, 2. motor including a control circuit, a transversely extendingequalizing member pivotally carried by said beam contiguous to one endthereof, means for transmitting motionv from said motor to said beamthrough said equalizing member, and switch means carried by saidequalizing member and operated by movement of the member on its pivot tointerrupt said control circuit and discontinue the operation of saidmotor.

9. In well pumping and drilling mechanism, a pivotally mounted walkingbeam, a motor, a transversely extending equalizing member carried bysaid beam contiguous to one end thereof, means for transmitting motionfrom said motor to said beam through said equalizing member, and switchmeans stationarily carried by said equalizing member and operated bytilting movement of the member in a plane extending transversely of thebeam to effect the stopping of said motor.

CLIFFORD R. ATHY.

